At least in the US, it is believed by a % of an entire faction that the absence of that government policy you mentioned is intentional, malicious, and designed to create new voters that are in the other faction’s pocket. And so the Great Replacement is a plan, rather than an observation, and this is where I see the controversy. The news here (“news”) is even pushing this narrative (I know this bc I was accosted with it today, in person), though I am not sure they use the terminology.